Monthly Outlook

The upcoming week will be changeable but less cold, with temperatures closer to seasonal values.

Early December should be milder and more settled for a while but from mid-month onwards there is even more uncertainty than usual.

Becoming less cold but remaining changeable

The weekend will become less cold but stay unsettled. A front will soon clear eastwards, but it will be followed by a developing low pressure system on Sunday. These features will bring a couple of rounds of rain, and it will still be just chilly enough for a little hill snow, mainly from northern England northwards.

Monday will be breezy with colder north-east to northerly winds temporarily setting in, bringing showers, some wintry. Most of the showers will be in windward areas, before a high pressure ridge topples across to make Tuesday drier in most areas. There will be widespread frost and risks of ice.

From Wednesday onwards, conditions will become much milder as broadly south-westerly flows develop, and a couple of bands of rain will move across from the Atlantic. Temperatures should rise above normal but Scotland could be closer to seasonal. A drier end to the week is possible as high pressure starts to build.

Milder and drier for a while

During the first week of December, the trend towards high pressure dominance should continue, so there should be drier conditions for most of the UK. The high pressure is most likely to be positioned in such a way that it will be accompanied by a relatively mild air mass, meaning that daytime temperatures should be widely near or a little above the December average. Nevertheless, occasionally clear and rather calm conditions overnight should mean risks of frost and perhaps fog patches.

Although most regions should be drier than normal, a couple of Atlantic frontal systems should nudge towards the UK, bringing occasional rain chances, mostly to northern and western regions, and probably most especially for Scotland, where some wintry precipitation could be possible over high ground. Elsewhere, a weakening front or two could bring a little rain farther southwards and eastwards, so it's unlikely to be completely dry. The risk to the forecast is that high pressure will position itself differently – more strongly over Scandinavia, for example – which would mean chances of colder flows developing.

Near normal temperatures but very uncertain

Through to the middle of December, similar conditions are most likely to stay in place, with high pressure not too far away from the UK but a chance of the odd frontal system edging in. However, ongoing upheavals in the upper atmosphere are a wildcard, and could start to have an impact on the weather as we go farther into the month, so uncertainty is particularly high. Temperatures will most probably be near or a little above average, but chilly and frosty nights are, of course, still likely.

After mid-month, there are some chances of conditions becoming wetter as low pressure systems move into western Europe. There could be some colder air pushing towards northern areas, where some wintriness might be possible. This may be dependent on high pressure building more strongly to the north or north-east. If it were to do so, then all areas would be colder.

In Tuesday's update, we will see if the longer-range models shed any more light on what might develop through December, and if they show any signs of colder weather returning.